US 12,263,446 B2
Electrodialysis process and bipolar membrane electrodialysis devices for silica removal
Ethan Demeter, The Woodlands, TX (US)
Assigned to TexOPCO, LLC, Houston, TX (US)
Filed by TexOPCO, LLC, Houston, TX (US)
Filed on Feb. 10, 2023, as Appl. No. 18/108,098.
Application 18/108,098 is a division of application No. 16/911,056, filed on Jun. 24, 2020, granted, now 11,577,202.
Claims priority of provisional application 62/866,407, filed on Jun. 25, 2019.
Prior Publication US 2023/0182078 A1, Jun. 15, 2023
Int. Cl. B01D 61/44 (2006.01); B01D 61/50 (2006.01); B01D 61/58 (2006.01); C02F 1/469 (2023.01); C02F 1/461 (2023.01); C02F 101/10 (2006.01); C02F 103/08 (2006.01)
CPC B01D 61/445 (2013.01) [B01D 61/50 (2013.01); B01D 61/58 (2013.01); C02F 1/4693 (2013.01); C02F 2001/46128 (2013.01); C02F 2101/10 (2013.01); C02F 2103/08 (2013.01); C02F 2201/4611 (2013.01); C02F 2201/46115 (2013.01); C02F 2209/06 (2013.01); C02F 2303/22 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method of purifying water comprising:
passing a feed water stream through one or more electrodialysis devices to remove dissolved ions and form a desalinated product stream, wherein each electrodialysis device of the one or more electrodialysis devices comprises a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream; and
routing the desalinated product stream to one or more bipolar membrane electrodialysis devices to remove silica, wherein each bipolar membrane electrodialysis device of the one or more bipolar membrane electrodialysis devices comprises a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream,
wherein the product inlet stream of a first bipolar membrane electrodialysis device of the one or more bipolar membranes of the one or more bipolar membrane electrodialysis devices comprises the product outlet stream of a first electrodialysis device of the one or more electrodialysis devices and wherein bipolar membranes of the electrodialysis devices form an alternative stack sandwiched between a set of electrodes with a positive and negative charge and wherein both a cationic exchange member and an anionic exchange member have a spacer on at least on surface facing the other ion-exchange membrane that includes a spacer border and a spacer mesh and wherein the spacer allows for at least one of two chambers that holds either an acid or a base as required to remove salt concentrations including removal of both dissolved ions and dissolved silica from the feed water stream and wherein placing the bipolar ion exchange membrane into an electrodialysis until leads to electrolysis of water at an interface between layers of the bipolar membrane such that liberated hydroxide (OH) ions can pas through an ion exchange material of the bipolar membrane and increase the pH of the stream in contact with the anion exchange material which results in an increase of the pH to a value greater than 10 to promote ionization of silica to a monovalent anion species that is transferred through an adjacent anion exchange membrane that results in a product stream devoid of ions and silica.